Airbag Control Unit Design – Complexity Leads to Numerous Misunderstands

More information

Main author

Zeidler, F.

Co-Authors

-

Type of media

-

Publication type

Lecture

Publication year

-

Publisher

11. EVU-Jahrestagung, Portoroz 2002

Citation

Zeidler, F. Zum Aufbau von Airbag-Kontrolleinheiten – Komplexität führt zu zahlreichen Missverständnissen. 11. EVU-Jahrestagung, Portoroz 2002

Crash Test

English, 7 pages, 8 figures, 6 references
Keywords: airbag, EES, calculation method

Although the main three physical theorems – conservation of momentum, energy, and angular momentum – are relatively simple, a "big mistake" with significant consequences has been made in the past during the development of accident reconstruction methods: The change of velocity (V) of a car in a crash is sometimes directly determined on the basis of the damage of this given car. However, damage and velocity do not necessarily correlate – in principle and from the physical point of view. Damage to an object can occur without changing the velocity of the center of gravity of this object; a change of velocity can happen without significant residual damage, especially in small modern cars with stiff structures. Although this statement is a truism, accident analyses ignoring this fact can sometimes be found. As a consequence, a working group of the ISO has tried to clarify the situation by defining special terms for accident reconstruction. In particular, the significant difference between the Energy Equivalent Speed (EES) and V must be re-addressed because incorrect application of the physical theorems might result in incorrect characterizations of an accident with misleading consequences, e.g. in regard to airbag deployment or expected injury outcome.